capacitor circuits: (1) Why are the elements enclosed in boxes? (2) Why are some of the nodes left hanging?
In computing the AC response of a Switched-Cap (SC) circuit, equivalent circuits of groups of elements are required. For this reason, it is necessary to keep these groups as such (and not break them up). The symbols for SC elements have been made up with the above consideration. In the frequency domain, each node needs to be represented by two nodes: an even node and an odd node. For transient simulation, the odd nodes can be ignored, which is achieved by connecting some dummy elements to the odd nodes within the element templates. For AC simulation, both even and odd sub-circuits need to be considered. In the circuit schematic, the even (odd) nodes of an element need to be conneced to the even (odd) nodes of other elements. If all of these connections are shown explicitly, the circuit diagram is bound to look messy and confusing. Therefore, the connections for the odd nodes are not shown explicitly. Instead, the odd nodes are connected by editing the element properties and assigning t
